Hand-held striking tools, such as claw hammers, sledge hammers, ball peen hammers, masonry hammers, and the like, have been used by people in a variety of disciplines for centuries as leveraged devices to provide a striking force to accomplish a variety of tasks. For example, a claw hammer is commonly used by carpenters to deliver sufficient striking force to drive a nail into wood. A sledge hammer is commonly used to deliver sufficient striking force for heavy work such as driving a stake, chisel, or wedge into masonry, stone, wood, or other hard materials. A masonry hammer is commonly used to strike masonry, stone, concrete, or similar hard materials for the purpose of breaking the material into smaller pieces. For example, to remove or modify an existing concrete walkway or portion thereof, a user may strike the concrete with the striking surface of the masonry hammer with sufficient force to break the concrete into smaller pieces, making it easier to remove the material.
Another common hand-held striking tool is a ball peen hammer, which has a substantially flat surface on one end and a rounded surface on the other end of its head, and is used to deliver sufficient striking force for shaping and fitting metal, and for driving machine chisels, rivet sets, machine wedges, and other similar tools.
Some hand-held striking devices, such as claw hammers, sledge hammers, masonry hammers and the like, have a traction texture on the striking surface of the impact head. Traction textures on a striking surface are commonly provided in a crosshatch, knurled, pebble-surfaced, grainy, or any sufficiently rough pattern. The purpose of traction texture is to improve friction between the impact head of a striking tool and an object being struck. Enhancing friction between the striking surface and an object being struck enhances a user's control of the direction and strength of impact. Traction textures are typically made by machining, drilling, etching, molding or other techniques well known in the art.
A problem with the traction texture on conventional impact heads is that the method by which the traction surfaces are produced results in a large number of small protruding elements from the striking surface. For example, milling, sawing, or molding grooves intersecting on a surface results in protrusions from the surface each having a quadrilateral cross-section, and of a length equal to the depth of the grooves. In many conventional textures pyramidal protrusions are molded into a surface providing a matrix of sharp points as a traction surface.
Protruding small structures as a traction surface have several drawbacks. One is that the structures tend to wear rather quickly causing the traction to deteriorate. Another is that striking a nail, rock, or some other hard object can cause one or more of the protruding structures to break or chip off, which not only deteriorates the traction but also may be quite dangerous.
What is clearly needed is an impact head traction surface that does not rely on numerous small protrusions to provide increased friction, and instead provides a contiguous striking surface that still enhances friction, and in which the arrangement of indentions is such as to provide particular friction-enhancing geometry.